Embodiments described herein relate generally to a blocking device, and more particularly, to a blocking device for blocking the insertion of a caging bolt into an entry aperture of a spring brake.
In trucks, buses and other vehicles, a spring brake may be located on the rear axle of the vehicle, and may be used as the parking brake. Spring brakes use air pressure and a spring to apply braking power. When driving, air pressure is applied, the spring is compressed, and the parking brake is disengaged. When the spring is decompressed due to low air pressure, the parking brake is applied. If there is loss of air pressure, the spring may be strong enough to apply braking power to the axle.
If there is no air pressure to disengage the parking brake, and if the vehicle needs to be moved, the spring can be mechanically released using a caging bolt. The caging bolt is inserted into an entry aperture of the spring brake cylinder, where the bolt is locked into place inside the spring parking brake chamber. The bolt is turned until the spring is released. However, an unauthorized user may mechanically release the parking brake when the authorized user has the parking brake engaged.